Hold-down clamp



June22, 1943. r w zL 2,322,707

HOLD DOWN CLAMP Filed Feb. 10, 1942 2 Sheets-Sheet l INVENTOR.

MAX E. WETZL EB A TTOPNEY June 22, 1943. M. E. WETZLER 2,322,707

HOLD DOWN CLAMP Filed Feb. 10, 1942 2 Sheets-Sheet 2 0 iwi INVENTOR.

MAX E. WE TZLEE.

BY Ma m/K ,4 7' Tag/wry as shown in Figs. 1 and 2-.

Patented June 22, 1943 UNITED PAT EN T F F I C E iidiin bowN oLAivrP Max E. wetnemmn Island 'City, N. Y. npplieationsetrtary 1o, 1'9t2,'seria1 No. 420,189

4 Claims.

My invention relates tohold down-clamps and more particularly to that type of hold down clamps which constitute attachments QI..drill presses,milling=machines and other apparatus.

The invention has forits object the provision ofa novel'hold down-clamp of the indicated type which may be readily and efficiently combined. with the machines for which it is intended and which is capable of being adjusted with a minimum of effort to effect its operative functions.

The invention contemplates further the pro- "vision of a novel hold-downclam'p in which the clamping instrumentalities are arranged to be adjusted'to operative positions at high speedand in a minimum of time.

'Otherobjects 'will appear from the description hereinafter and the features of novelty will be pointed out inthe claims.

In the accompanying drawings, which illustrate examplesof the invention without defining its limits,

'Fig. '1 is a perspective view of the novel hold down clamp embodied in a "conventional drill press;

Fig. 2 is a side elevation thereof withsparts in section;

Fig. 3 'is a plan view of the novel hold down "clamp;

Fig. 4 is a detail view illustrating a'hotherform of attaching means whereby the hold down =c'1arn'p may "be combined with the table "or bed-plate of another machine;

Fig. -5 is a side elevation partly brokehawa'y and in section, "of another fo'ihi' 'o-f the novel hold down clamp;

"base carries an upright member H which the form under discussion is of rectangular cross- "section and projects upwardly from said base Ill The upright member I l may be fastened upon the base H! in any convenient manner, for instance, as shown in the drawings by mean of two lugs I2 whichcons'titute integral parts of the base {it and a rivet or equivalent fastening device "[3 which extends transversely through the lugs l2 and upright member H to fix the latter in base 1 0.

The hold down clamp further includes a dampi-ng bracket I! provided with an elongated rectangular slot l5 whereby said clamping bracket H is slid'ably mounted on the upright member place on said with by means of a ball and socket connect-ion f8 and depends from the clamping bracket H as illustrated in Fig. 2. The opposite end of the clamping bracket ll includes an integral depending. arm IS in which a pressure developing spindle 20 i mounted in screwthreaded engagement therewith. A pressure member 24 ,is mounted upon the spindle 20 preferably by means of a ball and socket connection 22 so as to be in swivelled connection with said spindle 20 .as shown in Fig. 2. To facilitate the operation of the spindle 20 and its associated parts, a manipulating device, for instance, in the form of a thumb nut 23, may be fixed on said spindle. The clamping bracket I4 further carries a fulcrum member 24 secured in place in any suitable manner andextending transversely across the slot I 5 in engagement with one upright edge surface of the upright member I I.

Suitable means is provided for movably mounting the novel hold down clamp. in an associate whereby the novel hold down clamp is movably mounted on said bed-plate or table 25 is -il1us trated in the form of a screw 21 passing loosely through a plate or washer 2B and provided with a manipulating device, for instance, in the form of a wing nut 29. In such case, the base I!) is provided with an internally screwthreaded opening for the threaded accommodation of the screw 21.

In practice the plate or washer 28 lies in surface engagement with the lower face of the table or bed-plate 25 so as to span the slot26 thereof, and the screw 2'! projects upwardly through said slot into threaded connection with the threaded opening of the base I9. As the screw 21 .is screwed into said opening, the base l0 and the plate or washer 28 will be clamped upon opposite faces of the bed-plate or table 25 to securely the novel hold down clamp in the desired position in the drill press or other machine. It will be. noted that the screw 2'! may be shifted lengthwise of the slot 26 to vary the location of the hold down clamp upon the bed-plate or table 25.

In operation the work A is set in position upon the bed-plate or table 25 after which the clamping bracket I4 is moved downwardly upon the upright member II until the clamping member I! comes into engagement with said work A. It will be understood that at this stage the pressure member 2| is in loose sliding engagement with the one upright edge surface of the upright member ll. When the clamping member I! has reached the work A, the spindle is manipulated by means of the device 23 or its equivalent to force the pressure member 2| against the upright edge of the upright member ll. As the spindle 29 is thus manipulated, the depending arm l9 of the clamping bracket 14 will be forced away from the upright member ll to thereby force the fulcrum member 24 against the contiguous upright edge surface of the upright or devices.

When the particular operation on the work A has been completed, a reverse operation of the spindle 20 will quickly relieve the clamping pressure of the clamping member !'I on the work A and at the same time relieve the pressure of the pressure member 2| on the member It and correspondingly relieve the fulcrum member 24 from engagement with the opposite edge surface of the upright member H and thereby enable the clamping bracket l4 and its associated parts to be raised away from the work A and if desired to be completely removed from the upright member H. In any case, the work A is freed for removal from the machine.

The hold down clamp may be speedily and easily brought into clamping engagement with the next successive work A by sliding the clamping bracket I4 downwardly upon the upright member H until the work A is engaged by the clamping member I! and then repeating the operations hereinbefore described.

To enable the novel hold down clamp to be mounted in place upon the bed-plate or tables 25 of machines such as milling machines, the means exemplified in Fig. 4 may be provided. The bed-plates or tables 25' of milling machines and other machines are generally provided with slots 26 having under-cut portions 26 For mounting upon such bed-plates 25' the base It] is fixed upon a screw 21' having a circular head 29 and carrying a lock nut 21 and a washer 28'.

In practice the head 29 is inserted into the under-cut portion 25 of the slot 26 with the screw 21 projecting upwardly through the slot 28 and with the washer 28' resting upon the upper surface of the bed-plate or table 25 as shown in Fig. i. The novel hold-down clamp may be fixed upon the bed-plate or table 25 at any point in the slot 26 by simply screwing the nut 2'5 downwardly upon the screw El to force the head 29 of the screw 21' and the washer 28' into clamping engagement with the surface of the underclamping bracket 14 may be swung to different operative positions on the axis of the screw 21' or to an inoperative position out of the way, by simply loosening the nut 2! to relieve the clamping pressure of the washer 28 and screw head 29'. The same result may be obtained with the form shown in Figs. 1 and 2 by loosening the screw 21, which operation is however sometimes difficult because of the relative inaccessibility of the manipulating device 29 beneath the bed-plate or table 25.

In the form shown in Figs. 5 and 6, the upright member H is mounted upon a base l9 so as to project upwardly therefrom and is of rectangular cross-section as in the form first described.

The upright member 5 i may be secured upon the base Ill in the same way as previously set forth herein and may differ from the upright member ll only by being provided with a plurality of apertures 38 located in spaced relation lengthwise of said upright member I! and extending transversely therethrough. In this form of the cut portion 26 of the slot 26 and the upper surface of the bed-plate or table 25 respectively.

novel hold down clamp a fulcrum member 24' is carried by the clamping bracket Ml in the slot i5 thereof and is arranged to extend through a selected one of the apertures 36 to position the clamping bracket Id on the upright member H. Otherwise this form of the novel hold down clamp may be constructed in the same way as set forth hereinbefore. V

In practice the clamping bracket 14 is slidably adjusted lengthwise of the upright member H until the swivelled clamping member i7 comes into engagement with or in close proximity to the work A after which the fulcrum member 24' is inserted through the clamping bracket hi and through the particular aperture 30 which happens to be in proper position to receive said fulcrum member 2%. The spindle 253 is then operated as in the previous form, to force the pressure member 2! against the upright member H and thereby force the depending member IQ of the clamping bracket i l away from said upright member N". This causes the clamping bracket M to rock on the fulcrum member 24' and force the clamping member I! into clamping engagement with the work A. The base may be provided with either of the fastening means shown in Figs. 2 and 4 respectively for mounting this form of the vise in operative position in the machine.

The form of the novel hold down clamp shown in Figs. '7 and 8 comprises a base m similar to the previously mentioned bases it) and If! and supporting a member ll in upright position as in the form previously described. The upright member H is of cylindrical form and of any suitable dimensions dependent upon'the specific functions to be performed by the novel hold down clamp of which it forms a part. A clamping bracket I l corresponding generally in construction with the previously described clamping brackets is provided with an elongated slot I5 whereby the clamping bracket i i is slidabiy mounted on the upright member i l Preferably the slot I5 is curved at its opposite ends and at one end is sloping as indicated at Hi for the purpose to be more fully described hereinafter. The clamping bracket I l further carries a fulcrum member 24 located in the slot and extending transversely across the same in tangential engagement with the surface of the upright member l l a as shown in Fig. 8. The clamping bracket M carries a swivel clamping member l'i corresponding to the previously mentioned clamping member I! and is further provided in its depending arm l9 with a screwthreaded spindle 20 having a manipulating device 23 and a swivelled pressure member 21 The latter is preferably curved to fit the cylindrical surface of the upright member Il as shown in Fig. 8. The base ll) may be provided with any suitable means such as shown for instance in Figs. 2 and 4 for mounting this particular form of the hold down clamp in a drill press, milling machine or any other machine in which it may be useful.

The form of the hold down clamp shown in Figs. 7 and 8 functions and operates in the same way as previously described herein. In this lastmentioned form of the novel hold down clamp the clamping bracket I4 is capable of being swung on the axis of the upright member I l to various operative positions in the machine or to an inoperative position therein without in any way disturbing the means whereby the novel hold down clamp is mounted in the particular machine.

In all of its forms the inclined end walls It and l6 of the respective slots l5, l and It? enable the respective clamping brackets to develop the necessary rocking movements relatively to the upright members to bring the clamping members I? and I! into the most eiiicient clamping engagement with the particular work.

The novel hold down clamp regardless of its specific arrangement and construction is capable of being shifted into proper operative clamping relation with the work with maximum speed and without requiring any lengthy and tedious adjustments. The novel hold down clamp in addition to its other advantages serves to materially speed up the productive results of the respective machines with which said hold down clamp may be combined. In all of its forms the novel hold down clamp is simple in construction and requires no particular kill in its operation and setting in or combination with the machines for which it is designed.

Various changes in the specific forms shown and described may be made Within the scope of the claims without departing from the spirit of theinvention.

I claim:

1. A hold down clamp of the kind described comprising a base, an upright member fixed upon said base and projecting upwardly therefrom, a clamping bracket having a slot for slidably mounting said bracket on said upright member for adjustment lengthwise thereof, a swivelled clamping member carried by said clamping bracket for engagement with the work, a fulcrum member carried by said clamping bracket in the slot thereof and extending transversely of the upright member in engagement therewith, a pressure developing spindle carried by said clamping bracket in threaded engagement therewith, a pressure member in swivelled connection with said spindle for engagement with said upright member in opposed relation to said fulcrum member, said spindle co-operating with said fulcrum member to force said clamping member into clamping engagement with the work, and means whereby said base is adapted to be movably connected with the bed-plate of a machine to mount said hold .down clamp in said machine.

2. A hold down clamp of the kind described comprising a base, an upright member of rectangular cross-section fixed upon said base and projecting upwardly therefrom, a clamping bracket having an elongated rectangular slot for slidably mounting said bracket on said upright member for adjustment lengthwise thereof, a swivelled clamping member carried by said clamping bracket for engagement with the work, a fulcrum member carried by said clamping bracket in the slot thereof in engagement with an upright edge surface of said upright member, a pressure developing spindle carried by said clamping bracket in threaded engagement therewith, a pressure member in swivelled connection with said spindle for engagement with the opposite upright edge surface of said upright memher, said spindle co-operating with said fulcrum member to force said clamping member into clamping engagement with the work, and means whereby said base is adapted to be movably connected with the bed-plate of a machine to mount said hold down clamp in said machine.

3. A hold down clamp of the kind described comprising a base, an upright member of rectangular cross-section fixed upon said base and projecting upwardly therefrom, said upright member being provided with a plurality of spaced apertures extending transversely therethrough, a clamping bracket having an elongated rectangular slot for slidably mounting said clamping bracket on said upright member for adjustment lengthwise thereof, a swivelled clamping member carried by said clamping bracket for engagement with the work, a fulcrum member carried by said clamping bracket in the slot thereof and extending through a selected one of the apertures of said upright member, a pressure developing spindle carried by said, clamping bracket in threaded engagement therewith, a pressure member in swivelled connection with said spindle for engagement with an upright edge surface of said upright member, said spindle co-operating with said fulcrum member to force said clamping member into clamping engagement with the work, and means whereby said base is adapted to be movably connected with the bed-plate of a machine to mount said hold down clamp in said machine.

4. A hold down clamp of the kind described comprising a base, a cylindrical upright member fixed upon said base and projecting upwardly therefrom, a clamping bracket having an elongated slot for slidably mounting said clamping bracket on said upright member, a swivelled clamping member carried by said clamping bracket for engagement with the work, a fulcrum member carried by said clamping bracket in the slot thereof and extending transversely of the upright member in tangential engagement therewith, a pressure developing spindle carried by said clamping bracket in threaded engagement therewith, a pressure member in swivelled connection with said spindle and curved to fit said upright member in opposed relation to said fulcrum member, said spindle co-operating with said fulcrum member to force said clamping member into clamping engagement with the work, and means whereby said base is adapted to be movably connected with the bed-plate of a machine to mount said hold down clamp in the machine.

MAX E. WETZLER. 

